On Tue, Dec 07 2004, Jesper Juhl wrote:> > Problem reported by Katrina Tsipenyuk and the Fortify Software engineering> team in thread with subject "PROBLEM: unchecked returns from kmalloc() in> linux-2.6.10-rc2".> > Unfortunately I'm not very familliar with the code in question, and since > I didn't find a really good way to deal with a failing kmalloc() here I > settled for second best which is to add a BUG_ON() in case kmalloc fails. > This will at least crash in a sane way at the point the problem occoures > rather than getting strange problems at a (possibly) later time. If > someone who's familliar with how this code works has a better solution > then please step forward :) but in the mean time I think this is at least > a slight improvement over the current situation.> > Patch has been compile tested and boot tested and didn't blow up > instantly, but please review before applying.> > > Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>> > diff -up linux-2.6.10-rc3-bk2-orig/mm/slab.c linux-2.6.10-rc3-bk2/mm/slab.c> --- linux-2.6.10-rc3-bk2-orig/mm/slab.c 2004-12-06 22:24:56.000000000 +0100> +++ linux-2.6.10-rc3-bk2/mm/slab.c 2004-12-07 21:27:20.000000000 +0100> @@ -804,6 +804,7 @@ void __init kmem_cache_init(void)> void * ptr;> > ptr = kmalloc(sizeof(struct arraycache_init), GFP_KERNEL);> + BUG_ON(ptr == NULL); /* FIXME: Can a failed kmalloc be handled better? */> local_irq_disable();> BUG_ON(ac_data(&cache_cache) != &initarray_cache.cache);> memcpy(ptr, ac_data(&cache_cache), sizeof(struct arraycache_init));

This is pointless, as a NULL deref on memcpy will give you the exactsame info.